Enceladus

Enceladus moon of Saturn

The detailed information of Enceladus dates the arrival on Saturn in orbit of the probe Cassini on June 30th, 2004. Considering the observations realized from the images begun by Voyager 2, Enceladus was considered as an objective of first importance by the scientists of the mission Cassini, and several moved closer flying, at distances lower than 1500 kilometers, were programmed. The engines of the probe were even put in contribution to reduce the distance of passage during the flying over July 14th, 2005 to return it to approximately 172 kilometers, sharply lower than that initially foreseen (1000 km). Voyager 2 allowed to discover several types of tectonic training formations on Enceladus, among whom of the groups of linear faults and big curvilinear wrinkled bands. The later results obtained by Cassini suggest that the tectonic movements are the main cause of deformation of the crust on Enceladus. One of the most spectacular demonstrations of these tectonic movements are rift valleys (called fossae on Enceladus) which can reach near 200 kilometers long and 5 to 10 kilometers in width on one kilometer deep.

Enceladus

Moon of Saturn

Dimensions

513.2×502.8×496.6 km

Mass

8.6×1019 kg

Gravity

0.113 m/s2

Semi-major axis

237 948 km

Orbital period

1.370218 d

Eccentricity

0.0047

Escape velocity

0.239 km/s

Rotation period

synchronous

Discovered

August 28, 1789

Discovered by

William Herschel

Surface temperature

75 K

Apparent magnitude

11.7

Image: The detailed images of Enceladus date of arrival in the orbit of Saturn the Cassini spacecraft on 30 June 2004. Credit: NASA / JPL / Space Science Institute.

Image: The ring of particles which forms Enceladus around Saturn is called ring E. At least 11 other moons revolve on this ring and are constantly bombarded by the ice-cold particles emitted by Enceladus.

The geysers of Enceladus

Enceladus has, in spite of its small size (500 kilometers in diameter) a geologic activity. Almost seven times as small as our Moon, Enceladus knows perpetual modifications of its surface due to its geysers which spread of the ice and some liquid water, the likely consequences of the conditions of heat and pressure of its depths. The absence of crater in plains shows that some of these regions are old of less than 100 million years. Enceladus presents smoother zones of plains, events of ice, fish bones and long lines of fracture in its South Pole. These cracks are the source of the panache of ice which splash its orbit, and which accumulate on its trajectory. Geysers, situated in the South Pole of Enceladus, explode constantly, by ejecting particles of ice and by spreading a slender swirling trail in the trail of the moon, which eventually constitutes the ring of particles of ice which we know.

This one is supplied in every orbit of the moon around its planet. These particles can so collide with one of the moons enclosed in the ring E, including Enceladus itself when it crosses its own emissions. Anne Verbiscer: "we wondered why the other moons close to the ring E were so brilliant, although they are not geologically active as Enceladus. The answer, we know it henceforth, is that these other moons are riddled so to speak by the particles of ice ejected by Enceladus".

Image: Source: Cassini

Focus on Enceladus

Category: satellites of planets

Ice moon of Saturn shows its full splendor. In the foreground, the bright white of Enceladus detaches immense shadows of Saturn's rings as seen in the background. This photo was taken on 28 June 2007, at a distance of approximately 291 000 km, by the Cassini spacecraft, using its camera angle during its mission 'Equinox'. This perfectly round white side of Enceladus, measuring 504 km in diameter. The objective of the Cassini spacecraft is on 15 October 1997, the date of its introduction, the study of the planet Saturn and several of its satellites, including Titan. The space probe Cassini-Huygens, consisting of the orbiter Cassini and Huygens module is in orbit around the planet and is about to complete his mission 11 years.

Huygens, which aimed to land on the moon Titan, was raised on Titan on 14 January 2005 returning to Earth, remote 1.2 billion km, information and spectacular images.

The large stripe of Enceladus

The origin of this amazing scratch, several tens of kilometers on Enceladus is not explained, the Cassini spacecraft has been rescheduled in October 2008, by scientists to look more closely at the moon ice Saturn. What scientists are looking for is the possible presence of liquid water that may be under the frozen surface of Enceladus. Liquid water in extraterrestrial life, there is only one step in which the interest in great detail to explain this phenomenon. The dimensions of this stripe are impressive, both in depth, width and length. It could be due to a ground source heat kernel or back caused by a volcanic earthquake.

Ice Fountains of Enceladus

The surface of Enceladus, a moon of Saturn shows enormous eruptions of geysers of ice. A plume of ice have been photographed by the Cassini spacecraft during its flyby of Enceladus in November 2009. Deep canyons cut into the surface of Enceladus, where ice fountains rife. The plumes on upper of that image, just gush on the limb of Enceladus. These fountains of ice were found on images from the Cassini spacecraft in 2005 and since then scientists have been observing them, hoping for clues on the possible presence of underground oceans, where life could develop.

Image: Ice Fountains of Enceladus, taken by the Cassini spacecraft in November 2009.Credit: NASA/JPL/SSI; Mosaic: Emily Lakdawalla